In many pressure vessel applications, particularly those involving rotating machinery, it is extremely important to maintain the position of the end wall closure relatively constant under varying load conditions. In a case of a turbo machine, such as turbines and compressors, the end wall generally serves to support the stationary machine components in relation to the shaft mounted moving components. As can be seen, any axial shifting of the end wall, beyond allowable limits, will have a deleterious effect upon the operation of the machine and, in extreme cases, may lead to complete machine failure.
Various retaining or closure devices have been devised to accomplish the above-noted results as exemplified by Fisher in U.S. Pat. No. 2,342,186 and Evans in U.S. Pat. No. 3,552,789. However, these prior art devices all suffer from the same disadvantages in that they are complex, difficult to assemble and, more importantly, they are all subject to undesirable bending stresses which cause the retaining mechanisms to deflect under load. This deflection allows the end wall to shift axially, thus producing a misalignment of the interrelated components.